The quantum Ising model: finite sums and hyperbolic functions

We derive exact closed-form expressions for several sums leading to hyperbolic functions and discuss their applicability for studies of finite-size Ising spin chains. We show how they immediately lead to closed-form expressions for both fidelity susceptibility characterizing the quantum critical point and the coefficients of the counterdiabatic Hamiltonian enabling arbitrarily quick adiabatic driving of the system. Our results generalize and extend the sums presented in the popular Gradshteyn and Ryzhik Table of Integrals, Series, and Products.Comment: 7 pages, new title, small updates, published versio

Combining Neuro-Fuzzy Classifiers for Improved Generalisation and Reliability

In this paper a combination of neuro-fuzzy classifiers for improved classification performance and reliability is considered. A general fuzzy min-max (GFMM) classifier with agglomerative learning algorithm is used as a main building block. An alternative approach to combining individual classifier decisions involving the combination at the classifier model level is proposed. The resulting classifier complexity and transparency is comparable with classifiers generated during a single crossvalidation procedure while the improved classification performance and reduced variance is comparable to the ensemble of classifiers with combined (averaged/voted) decisions. We also illustrate how combining at the model level can be used for speeding up the training of GFMM classifiers for large data sets

Can God Promise Us a New Past? A Response to Lebens and Goldschmidt

Samuel Lebens and Tyron Goldschmidt provided original theodicies, which suggest that at one time God will change the past, either by erasing/substituting the sins of humans or erasing the whole entirety of evils. Both theodicies imply the idea that God can completely change the past without leaving any traces. In this paper, I argue that Lebens’ and Goldschmidt’s preferred model, which they call the scene-changing theory, is problematic. First, its complex metaphysical foundation could be replaced with presentism (roughly, the view in the ontology of time that only present things exist) without losing any substantial heuristics. Second, their theory either implies a controversial theory of truthmaking under presentistic and hyper-presentistic ontology or implies controversial views on the counting of events under presentistic and hyper-presentistic ontology. Thirdly, I will argue that any theory of elimination/substitution of evils of the past implies that there are unnecessary evils, which is inconsistent with God’s goodness

Improved alpha_s from Tau Decays

We present an update of the measurement of alpha_s(m_tau) from ALEPH tau hadronic spectral functions. We report a study of the perturbative prediction(s) showing that the fixed-order perturbation theory manifests convergence problems not presented in the contour-improved calculation. Potential systematic effects from quark-hadron duality violations are estimated to be within the quoted systematic errors. The fit result is alpha_s(m_tau) = 0.344 +- 0.005 +- 0.007, where the first error is experimental and the second theoretical. After evolution, the alpha_s(M_Z) determined from tau data is the most precise one to date, in agreement with the corresponding NNNLO value derived from Z decays.Comment: 4pages, 1 figure, Contribution to the proceedings of Moriond 2008, QCD sessio

The landscapes of tourism space

The author attempts to define the term ‘tourism landscape’. It is treated as an important attribute of tourism space therefore, apart from its definition, the author presents its characteristic features and various types of such spaces with differing tourism landscapes. The landscapes of tourism space are treated not only as tourism assets or attractions, but also as the consequences of tourism activity on the natural and cultural environment